Patentable/Patents/US-6566687
US-6566687

Metal induced self-aligned crystallization of Si layer for TFT

PublishedMay 20, 2003
Assigneenot available in USPTO data we have
Inventorsnot available in USPTO data we have
Technical Abstract

The present invention discloses a semiconductor device, a thin film transistor (TFT), and a process for forming a TFT. The semiconductor device according to the present invention comprises a top-gate type thin film transistor (TFT), said top-gate type TFT being formed on a substrate, said top-gate type TFT comprising: an insulating layer deposited on said substrate; a source electrode and a drain electrode formed from a metal-dopant compound, said metal-dopant compound being deposited on said insulating layer; a polycrystalline Si (poly-Si) layer deposited on said insulating layer and said source electrode and said drain electrode; an ohmic contact layer being formed between said metal-dopant compound and said poly-Si layer through migration of said dopant from said metal-dopant compound; a gate insulating layer deposited on said poly-Si layer; and a gate electrode formed on said gate insulating layer, wherein said poly-Si layer is crystallized by metal induced lateral crystallization.

Patent Claims
14 claims

Legal claims defining the scope of protection, as filed with the USPTO.

1

1. A semiconductor device comprising a top-gate type thin film transistor (TFT), said top-gate type TFT being formed on a substrate, said top-gate type TFT comprising: an insulating layer deposited on said substrate; a source electrode and a drain electrode formed from a metal-dopant compound, said metal-dopant compound being deposited on said insulating layer; a polycrystalline Si (poly-Si) layer deposited on said insulating layer and said source electrode and said drain electrode; an ohmic contact layer being formed between said metal-dopant compound and said poly-Si layer through migration of said dopant from said metal-dopant compound; a gate insulating layer deposited on said poly-Si layer; and a gate electrode formed on said gate insulating layer, wherein said poly-Si layer is crystallized by metal induced lateral crystallization.

2

2. The semiconductor device according to the claim 1 , wherein said metal-dopant compound comprises the elements selected from the group consisting of Ni, Fe, Co, Pt, Mo, Ti, B, and P.

3

3. The semiconductor device according to the claim 1 , wherein said metal-dopant compound is NiP or NiB.

4

4. The semiconductor device according to the claim 1 , wherein said metal-dopant compound is NiP and a concentration of P ranges from 0.5 at % to 10 at %.

5

5. The semiconductor device according to the claim 1 , wherein said metal-dopant compound is NiB and a concentration of B ranges from 0.25 at % to 2.0 at %.

6

6. The semiconductor device according to the claim 1 , wherein a light shielding layer is formed on said substrate and a plurality of said TFTs are arrayed to form an active matrix in said semiconductor device such that said semiconductor device is used as an active matrix liquid crystal display.

7

7. The semiconductor device according to the claim 1 , wherein a plurality of said TFTs are arrayed to form an active matrix in said semiconductor device such that said semiconductor device is used as an active matrix electro-luminescence display, or an image sensor.

8

8. A top-gate type thin film transistor (TFT), said top-gate type TFT being formed on a substrate, said top-gate type TFT comprising: an insulating layer deposited on said substrate; a source electrode and a drain electrode formed from a metal-dopant compound, said metal-dopant compound being deposited on said insulating layer; a polycrystalline Si (poly-Si) layer deposited on said insulating layer and said source electrode and said drain electrode; an ohmic contact layer being formed between said metal-dopant compound and said poly-Si layer through migration of said dopant from said metal-dopant compound; a gate insulating layer deposited on said poly-Si layer; and a gate electrode formed on said gate insulating layer, wherein said poly-Si layer is crystallized by metal induced lateral crystallization.

9

9. The top-gate type TFT according to the claim 8 , wherein said metal-dopant comprises the elements selected from the group consisting of Ni, Fe, Co, Pt, Mo, Ti, B, and P.

10

10. The top-gate type TFT according to the claim 8 , wherein said metal-dopant compound is NiP or NiB.

11

11. The top-gate type TFT according to the claim 8 , wherein said metal-dopant compound is NiP and a concentration of P ranges from 0.5 at % to 10 at %.

12

12. The top-gate type TFT according to the claim 8 , wherein said metal-dopant compound is NiB and a concentration of B ranges from 0.25 at % to 2.0 at %.

13

13. The top-gate type TFT according to the claim 8 , wherein a light shielding layer is formed on said substrate and a plurality of said TFTs are arrayed to form an active matrix such that said top-gate type TFTs are included in an active matrix liquid crystal display.

14

14. The top-gate type TFT according to the claim 8 , wherein a plurality of said TFTs are arrayed to form an active matrix such that said top-gate type TFTs are included in an active matrix electro-luminescence display, or an image sensor.

Classification Codes (CPC)

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Patent Metadata

Filing Date

January 18, 2001

Publication Date

May 20, 2003

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